1. Field of the Invention
The present invention relates to a keypad assembly, and more particular to a manufacturing method of a thin keypad assembly.
2. Description of Prior Art
In addition to the function of a mobile phone, consumers also take other factors including the innovative appearance and the compact size of the mobile phone into consideration for the purchase the mobile phone. Therefore, some mobile phones print color patterns on the housing or keypad or produce three-dimensional lines directly on the housing of the mobile phone to improve the added-value of the product and promote the purchasing desire of the consumers.
Referring to FIG. 1A and a traditional way of producing three-dimensional lines as disclosed in R.O.C. Pat. No. M304441, the patented technology discloses a manufacturing method of a thin keypad assembly that attaches a first transparent layer 2a onto a substrate 1a, a first color layer 3a and a color opening area 31a onto the first transparent layer 2a, a second transparent layer 4a onto the first color layer 3a, and a second color layer 5 onto the second transparent layer 4a for providing an external look with different colors and lines for the depth of field by the aforementioned display structure and mode for the requirement of different visual appearances or functions. However, such manufacturing method takes too much time and efforts, and thus incurring a high manufacturing cost of the product easily.
Referring to FIG. 1B and R.O.C. Pat. No. M301397 for another keypad assembly with lines manufactured therein, a lines layer 1b is included between a thin film layer 2b and an elastic layer 3b for producing a flare effect. Since a lines layer 1b is created between the thin film layer 2b and the elastic layer 3b, therefore such patented technology not only adds more steps to the production or manufacturing procedure, but also consumes much manufacturing time and increases the thickness of the keypad. Obviously, an increased thickness is a disadvantage to the design of a thin film keypad.